If you, like me, were at the Stephen Law vs William Lane Craig debate, your jaw will have dropped when Craig, in defence of God vis-a-vis animal suffering and the problem of evil, claimed that animals don’t suffer pain.
He claimed that most animals didn’t have the conscious awareness of pain that humans and other primates do. He was solely relying on the work of Michael Murray in Nature Red in Tooth and Claw: Theism and the Problem of Animal Suffering. This book sets out that there are, broadly speaking, three levels of pain suffering and related awareness, amoebas in the first, humans in the last, and most higher animals in the middle. They feel pain but are not consciously aware of it in the same way as humans are.